That's why I said "keep your ship level". Should probably of mentioned also "zero throttle", and "don't touch any thrusters".

Every bit you say about losing control is true, if you don't keep your ship level when coming out of glide. On take-off you need to stay level and use only upward thrust (those same magic bottom thrusters) for agonizingly long time, to get high enough to engage hyperspace even if you lose altitude (and partly attitude) control. Or to go into supercruise with a bit of trickery (the tricky part is to maintain enough upwards momentum to point your ship's nose above 45° and gain enough forward momentum so your velocity vector points that way too).
Here's a video of me fumbling down and eveng successfully getting away from 11G planet, showing some of the difficulties and one way to safely land (until I tapped thrust down

).
Source: https://www.youtube.com/watch?v=ok8QYnT3gzs
All in all, I concur, saying "thrust does not matter" is inaccurate, even if it is true that you can land (and even take off) on any gravity with any thrusters.
How many time did you fly one of those fits? I went to Colonia twice with this Anaconda so fitted, in one occasion I crashed simply because gravity plus no control authority plus weak thrusters meant that the ship was not under control whatever I was doing.
It's not only on the vertical axis that we meed thrust, that's why a stronger thruster provides with more control authority, when you ignitiate a motion, you need to be able to stop it, in all axis, and I doubt very much that you would have succedeed in landing such an underpowered ship in the same conditions.
For the rest, I know how to land a ship even on a high G planet, but physics are the same for everyone and come a point where you just can't beat them, so better a shorter range than being sorry and as I said, I never crashed again after I adjusted my fits.
I do use quite beefy thrusters though, 5D with G5 dirty drive here, which does help. That said, I first practiced high G landing on Achenar 3 with an Anaconda & unmodded 6D thrusters, but it was a long time ago.
Unmodded 6D thrusters is not extreme and certainly nowhere near the fits they suggested for getting the sort of range they achieved, we're talking 4 instead of 6D for extreme range.
I can remember upgrading my Krait Phantom from a 4D to an engineered 6D, Dirty Drag Drives XX, after I went through the same experience with the Krait, as I said, I used one of the Fuel Rats built with some modifications, reason I used their fit is that they need long range but also safety to carry over their rescue missions, it is proven.
Suggested Ship Loadouts.
So here you go, you might be able to get away with some level of low power but down to a point, past that, it's asking for trouble and people who are just pushing the long range envelope as I did without anticipating this sort of issue aren't going to enjoy it for very long, reason why I gave this warning.
btw, I wasn't the only one to complain about it, especially the Anaconda, people had trouble negotiatriing Suns, couldn't land safely same as myself etc, putting a fit together "on paper" is one thing, flying it in a wide range of conditions another, I probably wouldn't have known if I havent traveled to Colonia and come across this particular planet.